Apparatus for making plastic buckets

ABSTRACT

1. A container forming machine comprising a frame, a turret mounted for rotation on the frame, a plurality of forms having side wall and bottom wall surfaces mounted on the turret and each adapted to receive a side wall blank about its side wall surface, a first station on the frame adjacent the turret and means in that station for applying a blank to each form as each form enters said station, a magazine mounted on the frame in the first station for holding a side wall blank above the form in that station, means for removing a blank from said magazine, said means in the first station including said removing means and forming means for partially forming each blank into a cone and thereafter placing the partially formed conical side wall blank on the form in that stations, stop means mounted on each form for registering the blanks on them in the desired position, heating and clamping means mounted on the frame in association with each form for heating the sides of the blank by positioning a radiant heater between facing surfaces of the blank to heat said facing surfaces to be lapped and thereafter clamping said facing surfaces together in lapped relation to form a lapped side seam for the container blank, a second station on the frame disposed adjacent the first station in which station a bottom blank may be applied to the forms as they enter said station with the bottom including a peripheral flange lying in face to face contact with the inner surface of the side wall blank on the form over at least a portion of the axial extent of the flange when both side wall and bottom blanks are in place on the forms, a heater mounted on the frame in a third station adjacent the turret and movable to engage at least the side wall blank on the turret to make it molten at the region where it engages the bottom as each form is in that station, a forming tool mounted in a fourth station on the frame adjacent the turret for shaping and sealing the molten portion of at least the side wall while on the form and immediately after it is heated to precisely shape the union between the bottom and side wall, and a fifth station adjacent the frame through which each form passes for removing the container of each form.

NOV. 5, 1914 ac ETTAL 3,846,207

APPARATUS FOR MAKING PLASTIC BUCKETS ll Sheets-Sheet 1 Original FiledFeb. 2, 1970 Nov. 5, 1974 G. Mac ETAL 3,846,207

APPARATUS FOR MAKING PLASTIC BUCKETS ll Sheets-Sheet 2 Original FiledFeb.

FIG. 4

Nov. 5, 1974 G. MaC ETAL 3,846,207

APPARATUS FOR MAKING PLASTIC BUCKETS Original Filed Feb. 2, 1970 llSheets-Sheet 3 FIG. l3

Nov. 5, 1974 s. M DANlEL EAL 3 APPARATUS FOR MAKING PLASTIC BUCKETS llSheets-Sheet 4 Original Filed Feb.

FIGS

FIG. IO

NOV. 5, 1914 G. MacD EI'AL 3,846,207

APPARATUS FOR MAKING PLASTIC BUCKETS ll Sheets-Sheet 5 Original FiledFeb. 2, 1970 Nov. 5, 1974 G. M DANlEL ETAL 3.845.207

APPARATUS FOR MAKING PLASTIC BUCKETS ll Sheets-Sheet 6 Original FiledFeb. 2, 1970 FIG.

NOV. 5, 1914 G. MacD E ET AL 3,846,207

APPARATUS FOR MAKING PLASTIC BUCKETS Original Filed Feb. 2, 1970 llSheets-Sheet 7 L 28 HC.) g 5 no i E t\ \3 FIG. I?

FIG. I9

Nov. 5, 1914 C ANI ETAL 3,846,207

APPARATUS FOR MAKING PLASTIC BUCKETS Original Filed Feb. 2, 1970 llSheets-Sheet 8 I70 I74 I76 NOV. 5, 1914 G, Mac ETAL 3,846,207

APPARATUS FOR MAKING PLASTIC BUCKETS Original Filed Feb. 2, 1970 llShee1 :s-Sheet 9 Nov. 5, 1914 G. M DANIEL ETAL APPARATUS FOR MAKINGPLASTIC BUCKETS ll SheetsSheet 10 Original Filed Feb. 2, 1970 NOV. 5,1914 G. Mac ETAL APPARATUS FOR MAKING PLASTIC BUCKETS 11 Sheets-Sheet 11Original Filed Feb. 2, 1970 United States Patent 3,846,207 APPARATUS FORMAKING PLASTIC BUCKETS Gene MacDaniel, Lithonia, and Howell T. McElvy,Decatur, Ga., assignors to Sweetheart Plastics, Inc., Wilmington, Del.

Original application Feb. 2, 1970, Ser. No. 7,955, now Patent No.3,673,033. Divided and this application Apr. 17, 1972, Ser. No. 244,985

Int. Cl. B31b 3/02, 3/60 US. Cl. 156-443 9 Claims ABSTRACT OF THEDISCLOSURE A method and machine for producing two-piece containerswherein a turret carrying a plurality of container forms each hasapplied to it a side wall and a separately preshaped bottom, an as theturret rotates through successive stations, the side seam of the sidewall is heat sealed closed, and the preformed bottom is heat sealed tothe bottom of the side wall. Thereafter on a secondary turret thecontainer rim is rolled and the fully formed container is ejected fromthe machine.

This application is a divisional application of Ser. No. 7,955, filedFeb. 2, 1970, and now issued as US. Pat. No. 3,673,033.

This invention relates to relatively large two-piece insulatedcontainers and more particularly comprises a new and improved method andapparatus for forming such containers.

There is at the present time a growing demand for disposable containersin large sizes. This growth in part is the result of the rapidly growingbusiness of franchise take-out food vendors such as the roadside friedchicken stands, as well as the result of rapidly increasing labor coststhat make reusable containers in all industries prohibitively expensive.While in the disposable container industry plastic has captured asignificant percentage of the market in small container sizes, thus farthe larger containers of the one gallon size range are almostexclusively still made of paper. This is particularly true in theinsulated bucket or tub field where heretofore no one has developed acommercially competitive insulated plastic tub. Conventionally the largetubs used for example as chicken buckets are made of double wrappedpaper. The heavy duty double wrapped paper buckets are expensive, haveonly limited insulating properties, and generally are subject to thesame failings as paper food containers made in smaller sizes, i.e. theyhave a taste and odor which effects the contents, they absorb moisture,etc. Copend: ing application Ser. No. 879,448, filed Nov. 24, 1969, nowPat. No. 3,664,568, entitled Insulated Plastic Bucket, describes andclaims one product which may be produced by the method and apparatus ofthis invention.

Heretofore efforts to make large containers of plastic have takenseveral directions, but none thus far have produced a container that issatisfactory for the purposes served by the double wrapped paperbuckets. The large injection molded containers are too expensive tomanufacture to be considered truly disposable, and they have poorinsulating properties. Efforts to make the containers in one piece fromsheet foam by forming techniques have been successful because of thethickness of the stock and the necessary depth of the draw.

The method and apparatus of this invention embody the concept ofpreshaping the bottom of the container and applying it to a containerform where it is joined to the side wall which is wrapped about thefoam. The side wall seam is heat sealed closed, and the preshaped bottomis heat sealed to the side wall, and the side wall is subsequentlystiffened by rolling the rim.

"ice

In the drawing: FIG. 1 is a cross-sectional view of one container thatmay be manufactured by the method and apparatus of this invention;

FIG. 1A is a plan view of the side wall blank in the container of FIG.1;

FIG. 1B is a fragmentary detail of the container of FIG. 1;

FIG. 2 is a cross-sectional view of another container that may bemanufactured by the method and apparatus of this invention;

FIG. 3 is a plan view of the apparatus of this invention;

FIG. 4 is a side view of the apparatus of FIG. 3;

FIGS. 5-7 illustrate successive steps performed by the apparatus ofFIGS. 3 and 4 to make the container of FIG. 1;

FIG. 8 is a plan view of the side wall blank magazine forming part ofthe apparatus of FIGS. 3 and 4;

FIG. 9 is a front view of the magazine;

FIG. 10 is a side view of the magazine;

FIG. 11 is a side view of the transport mechanism for applying theblanks to the forms;

FIG. 12 is a front view of the transport mechanism;

FIGS. 13 to 16 are diagrammatic illustrations of the steps of drawingthe blanks from the magazine to the transport mechanism;

FIG. 17 is a detail view of one of the frustoconical forms and otherassociated parts;

FIG. 18 is a rear view of the form of FIG. 17 with the side seam sealingmechanism open;

FIGS. 1921 diagrammatic illustrations of the sequence of steps to sealthe side seam;

FIG. 22 is a fragmentary side view of the apparatus of FIGS. 3 and 4showing the main turret drive and the actuating mechanism for the sideseam heater;

FIG. 23 is a side view of the actuating mechanism for the side seamheater;

FIG. 24 is a side view of the bottom edge heating assembly;

FIG. 25 is a side view of the bottom edge spinning and sealing assembly;

FIG. 26 is a side view of the rim heating assembly on the rimmingturret;

FIG. 27 is a side view of the rim rolling assembly on the rimmingturret;

FIG. 28 is a side view of the ejecting mechanism of the rimming turret;and

FIGS. 2932 illustrate the sequence of steps for making the container ofFIG. 2, as the steps may be performed on the apparatus of thisinvention.

Before describing the method and apparatus of this invention, twoproducts which may be produced by it will be described. They are shownin FIGS. 1 and 2.

The bucket 20 shown in FIG. 1 has a side wall 22 and a bottom 24. Theside wall is made from a blank shown in FIG. 1A having curved top andbottom edges 26 and 28 and diverging side edges 30 and 32 so that whenthe side wall is rolled into the container shape it is frustoconicalwith the desired side wall taper to facilitate nesting. The side wall 22and the bottom 24 are made from expanded styrene sheets and maytypically have a stock thickness of approximately .112 inch and weighapproximately 19 grams per square foot with a cell size of 4 to 5 mils.It is to be understood that these containers and the dimensions givenare merely exemplary of what may be made by the method and apparatus ofthis invention, and the method and apparatus may be used to makecontainers of a very wide range of sizes and shapes.

The side edges 30 and 32 of the side wall blank are overlapped andcompressed together in the manner shown in FIGS. 19 to 21 and describedin detail below to form a liquid tigh t seam running from top to bottomof the side wall. The total thickness of the overlapped portion of theside wall is less than twice the stock thickness and preferably does notappreciably exceed the single stock thickness of the material.

The bottom of the container is preshaped before assembly from sheetstock, either by conventional forming techniques, matched molding, orother process. When formed, the bottom is configured as shown in FIG. 1with a central portion 34 and a peripheral skirt 36 which extendsdownwardly from the central portion 34 generally with a very slightlydownward flare of approximately 3. The outer diameter of the skirt 36 atthe bottom edge 38 is equal to or slightly larger than the innerdiameter of the bottom edge 40 of the side wall 22 so that when thebottom is assembled as described below the outer sur face of the skirt36 at its lower edge engages the inner surface of the lower margin 40 ofthe side wall. When the bottom 24 and the side wall 22 are assembledtogether on the machine of this invention the lower margin 40 of theside wall is fused through a very small portion of its height as issuggested in FIG. 1B. From that point the skirt and side wall diverge inan upward direction to form a well 42 which is particularly desirable asa grease trough when buckets are used to contain fried foods such aschicken. In a one gallon tub size, typically the height of skirt 36measured from its lower margin to the upper surface of the centralportion 34 is approximately inch, and the trough 42 has a height ofapproximately inch. The volume of the trough is of course a function ofthe taper of the side wall 32, which typically may be approximately 12.

To enhance the appearance of the tub, broaden its applications, andincrease its stiffness at the mouth 44, the rim 46 is rolled as shown inFIG. 1, and preferably the material of the rim is somewhat expanded soas to further increase its stiffness. The manner in which the rim isshaped is described in detail below also.

The container 50 shown in FIG. 2 diflers from the container 20 of FIG. 1in the construction of the bottom. The container 50 has a side wall 52with a rolled rim 54 identical to that of FIG. 1. The bottom includes agenerally horizontal central portion 58 which may be dished upwardly ifdesired to increase its stiffness and oppose sagging, and the bottomalso includes a peripheral skirt 60 which extends upwardly from themargin of the central portion 58. The skirt 60 is upwardly flared sothat it forms the same angle with the vertical as does the side wall 52.This flare may typically be an angle of 12.

In FIG. 2A the details of the connection between the skirt 60 and theside wall 52 are shown. The bottom 56 is preformed in the shape shown inFIG. 2, and the axial extent of the skirt 60 is substantially the sameas the skirt 36 in the embodiment of FIG. 1. The skirt 60 is heat sealedto the inner side of the side wall 52, and the bottom 62 of the sidewall is wrapped about the radius 64 which joins the skirt 60 and thewall 58 to form a smooth juncture between the side wall of the containerand the bottom. The lower edge 62 of the side wall where it wraps aboutthe radius 64 is compressed so as to form a smooth union between theouter surface 66 of the side wall and the lower surface 68 of the bottom58.

The apparatus of FIGS. 3 to 28 forms the containers of FIGS. 1 and 2,and is described in connection with FIGS. -7 and 29-32 which show thesequence of steps in assembling the containers.

The machine shown in FIGS. 3 and 4 includes a frame 70 having a numberof adjustable legs 72 joined by a number of horizontal braces and plates74, 76, and 78 to provide a stable platform for the assembly and supportmany of the parts of the machine.

A 'bed 80, hexagonal in shape, is supported adjacent the top of a numberof the legs on the right side of the machine as viewed in FIGS. 3 and 4,and a shaft 82 extends upwardly through the bed 80 and forms the centerof a six station forming turret 84. The turret includes in the formshown, six frustoconical container forms 86 which move from station tostation about the axis of the shaft 82 when the shaft rotates. In FIG.3, form 86A is disposed in station I, form 86B in station II, form 86Cin station III, form 86D in station IV, form 86E in station V, and form86F in station VI. The drive 87 provided for the shaft 82 indexes theturret so that the forms move step by step successively from station Ito VI. The forms stop at each of the stations while various operationsare performed in the assembling of the container.

Briefly, the steps performed in stations I to VI are as follows:

Station Iside wall blank B is applied to the form.

FStation IIthe preformed bottom 24 is inserted within the margin of theside wall as suggested in FIG. 5, and the side edges 30 and 32 of theblank B are heated.

Stations III and IV-the bottom edges of the bottom and side wall blankare heated as suggested in FIG. 6, and the previously heated side edges30 and 32 are firmly pressed together to seal them in overlappedrelation as suggested in FIG. 21.

Station Vthe heated bottom and side wall margin are spun to form a sealas suggested in FIG. 7.

Station VI-the container is removed from the form and placed on thesecond turret of the machine for rim forming.

The details of the machine and the steps performed in each station aredescribed below under appropriate headmgs.

STATION I-MAGAZIN'E In station I the side wall blanks B are applied oneat a time to the container forms 86 as the forms enter and stop in thatstation. In FIGS. 8 to 16 the machine and operation are shown.

In FIGS. 8 to 10 the loading magazine 89 is shown supported on framemember 90. The magazine includes a pair of spaced generally horizontalplates 92 mounted slightly above a pair of support rods 94 whichtogether sandwich the flat side wall blank B. A guide plate 96 having anupturned lip 97 is secured to the front ends of the plates 92 while theforward ends of the support rods 94. are bent downwardly to form anopening to the area between the support rods and plate to introduce theblank.

A substantial horizontal gap exists between the plates 92, and the blankB is exposed bet-ween them. A center bar 98 bridges the gap from frontto rear so as to form a top support for the blank B when an upwardlydirected force is exerted against it by the mechanical movement ofsuction cups 100 that form part of the transport mecha nism 99 shown inFIGS. 1116. An operator standing beside the machine feeds the blanks oneat a time into the slot so that the blank rests on the bars 94 below theplates 92, and stops 102 secured to the lower surfaces of the plates 92position the blank accurately in the magazine. As the rods 94 aresuspended from their rear ends 104 to the bottom of plates 92, they aresomewhat flexible, and front end rod supports 106 underlie the outerends of the rods to prevent them from sagging or bending appreciably.Thus each blank B placed in the magazine is supported from beneath bythe spaced bars 94.

From the magazine the blanks are drawn one at a time downwardly betweenthe bars 94 onto folding plates 108 forming part of the transportmechanism 99 shown in FIGS. 11 and 12, and after folding each blank isplaced about the form 86 in station I. FIGS. 13 to 16 show schematicallyhow the blanks are drawn from the bars 94 onto the folding plates. Apair of suction cups 100 disposed one behind the other move upwardly instation I and grasp the bottom side of the blank B, immediately beneaththe bridge 98. In this way firm suctional contact is made with theblank, and as the suction cups move downwardly between the foldingplates 108 of the transport mechanism, which are widely separated, theblank B bows,

as shown in FIG. 14 because the blank is wider than the gap between thestationary bars 94. Downward travel of the suction cup continues untilthe side edges 30 and 32 of the blank B clear the rods 94, andsimultaneously the folding plates 108 move toward one another until theyultimately engage the blank. While the suction cups continue to hold theblank, the folding plates move to their innermost positions where theyengage the blank firmly and form the blank into a rather deep U-shapedconfiguration as suggested in FIG. 16. The radius of curvature of theblank as it is supported by the folding plates 108 just about matchesthe radius of the form 86, and therefore when the folding plates 108move toward the center of the machine in the direction of the form 86 assuggested in FIG. 11, the blank slips about the cone. The manner inwhich the suction cups assembly and the folding plates move so as todraw the blanks from the magazine and place them on the form 86 isclearly illustrated in FIGS. 11 and 12.

FRUSTOCONICAL FORMS In FIG. 17 some of the details of one form areshown. A pair of removable bands 110 and 110' are mounted on thecone-shaped form 86, and these bands act as stops to accurately positioneach blank B as it is placed about the cone in the first instance by thefolding plates 108. It will be noted that the blank B extends from thefirst stop 110 to a position wherein its bottom edge 28 lies beyond thebottom 112 of the form 86. End plates 114 (see FIG. 12) carried by thefolding plates 108 also serve as stops to push the blank B against thestop 110 on the form 86. When larger containers are being made, the stop110' is utilized and the stop 110 is removed.

STATION ITRANSPORT MECHANISM In FIGS. 11 and 12 the transport mechanismis shown in detail. The folding plates 108 are each shown carriedseparately by two generally vertically extending arms 140 and 142 whichin turn are joined together adjacent their midsections by links 144 and146. The links are connected at their extremes to the respective arms,and at their adjacent ends they are connected to block 148 in turnmounted on and moveable with the rod 150 of cylinder 152. The rod 150 atits upper end carries the pair of suction cups 100 which are connectedto a fitting 154 so that they may be joined to a vacuum pump so as toactivate the suction cups.

The bottoms of the arms 140 and 142 are pivotally connected by pins 155to posts 156 which in turn are mounted on shaft 158 supported onbearings 160 secured to the bottom frame member 76.

When the cylinder 152 is energized to elevate rod 150 and suction cups100, the block 148 also rises and the links 144 and 14.6 spread the arms140 and 142 so as to separate the folding plates 108. The links 144 and146 assume a substantially horizontal position when the block 148 iselevated on the rod 150, and the arms 140 and 142 pivot on the pins 155.Thus the suction cups and folding plates operate together in a mannersuggested in FIGS. 1316 so as to perform the folding operation.

In order to place the blank B about the form 86 after it is taken fromthe magazine, the whole transport mechanism moves rearwardly toward thecenter of the turret as suggested in FIG. 11. In that figure the brokenline position is that assumed by the assembly when the blanks are beingdrawn down from the magazine 89 onto the folding plates 108. After theblank is folded and held firmly on the plates, the mechanism moves tothe position shown in full lines wherein the plates 108 and blank Bsurround the form 86. This motion is carried out by lever 149 which iscarried by the shaft 158. When the lever is pulled at the top toward thecenter of the machine by rod 151, the shaft 158 turns throughapproximately 20 and carries the arms 140 and 142 and associated partswith it, and the blank is properly oriented on the form as describedabove in connection with FIG. 17.

STATIONS I-IV-SEALING SIDE SEAM The apparatus described above places theside wall blank B about the form 86. In stations I-IV the apparatusshown in FIGS. 17 to 23 serves to position the side edges 30 and 32 ofthe blank B in place and heat seal them together.

Each of the six forms 86 has a first pressure bar 116 on the left asviewed from the small diameter end of the form for holding the loweredge 30 of the two edges of the blank in place, and a second pressurebar 118 on the right which applies pressure to the overlapped edges tocause them to fuse together after they have been sufl'iciently heated.The pressure bars 116 and 118 are supported on the turret platform 120which is mounted on shaft 82 and rotates with it. Mounting brackets 122and 124 that carry the form 86 each pivotally supports a pair of spacedhinge plates 126 and 128 that in turn carry the pressure bars 116 and118. Disposed between the pairs of plates 126 and 128 are sprockets 130and 132 respectively (see FIG. 17) that engage chains 134 and 136 (seeFIG. 18) to cause the bars 116 and 118 to pivot through the variouspositions shown in FIGS. 19 to 21. In FIGS. 18 and 19 the two pressurebars 116 and 118 are shown in their extreme open position whereinneither is positioned to engage the blank edges on the form 86, andneither is in a position to interfere with the application of the blankto the form. The raised edges of the blank B as shown in FIG. 12 passbetween the bars as the transport moves forward to apply the blank.Immediately after the blank is applied, and just as the form begins toleave station I the first pressure bar 116 swings from the positionshown in FIG. 19 to that shown in FIG. 20 where it presses and holdsdown the lower edge 30 of the blank B on the slightly flattened formside wall. At the same time radiant heater rod 140 is moved into placeadjacent the end of exposed edge 30 and the adjacent edge 32.

The bar 118 also moves from the position shown in FIG. 19 to engage theedge 32 and move it adjacent the radiant heater rod. It will be noted inFIG. 20 that the edge 32 is not in contact with the edge 30, but ratheris positioned immediately adjacent the heating rod 140 so that it toomay be heated by it. The movement of the bar 118 takes place as the formreaches station II, While the radiant heater and the bar 116 move to theposition shown in FIG. 31 during actual movement of the form 86 fromstation I to station II.

In station III as shown in FIG. 21 the bar 118 moves against the edge 32of the blank B so as to press it firmly against the exposed end of edge30. The pressure applied by the bar 118 serve not only to seal the twoedges together but in addition to compress the seam so that the stockthickness of the container at the seam is only slightly greater than thestock thickness of the remainder of the container side wall. The bars116 and 118 remain in the position shown in FIG. 21 in stations III andIV so that sufficient time is allowed for proper bonding of the twolapped edges. As the form moves into stations V and VI the bars 116 and118 are open substantially to the position shown in FIG. 19. Asindicated, the chain and sprocket mechanism shown in FIG. 18 incooperation with an actuator (not shovm) disposed beneath the turretmove the bars to the various positions described.

In FIGS. 22 and 23 the actuating mechanism for the heater rod 140 isshown. The rod 140 is carried between a pair of supports in turnpivotally mounted on a rocket shaft 172 which is carried by arms 174fixed to the frame of the machine. The rocker shaft 172 is connected toa crank 176 at one end, and rotation of the crank arm 176 about the axisof the rocker shaft rotates the shaft to in turn raise and lower thesupports 170' that carry the heater rod 140. The free end of the crankarm 176 is connected to a rod 178 which extends downwardly along theside of the machine, and the bottom of rod 178 in turn is anchored tothe outer end of radial lever 180. When the outer end of lever 180 movesdownwardly, the rod 178 moves downwardly with it and turns the crank. Asshown in FIG. 22 the lever 186 is pivoted about the support pin 182, andthe inner end 184 of the lever moves up and down in response to up anddown movement of actuator 186. Thus the actuator 186 controls themovement of the heater rod 140 between the positions shown in FIGS. 19and 20; that is, between its operative and inoperative positions.

MAIN TURRET AND ACTUATOR DRIVE FIG. 22 also illustrates in detail thedrive for the turret 84. In that figure the drive mechanism 87 is shownto include a main drive motor 190 connected to gear box 192 whichrotates the main shaft 82 in stepwise rotation so that the several forms86 move from station to station and pause in each. The gear box 192 alsorotates cam 194 continuously, and a track 195 in the outer face 196 ofthe cam controls the cam follower 198 carried by the vertically moveablecolumn 200. The column 200 in turn carries a horizontal foot 202 whichsupports and moves the actuator 186. That is, as the cam 194 rotates,the cam following 198 moves up and down as determined by the contours ofthe track in the cam face 196 so as to raise and lower the column 200which through the foot 202 raises and lowers the actuator.

In FIG. 22 a sprocket 204 is shown carried by the main turret shaft 82,and its chain 206 rotates the turret 208 of the rimming mechanism whichforms part of the assembly and which is described in detail below.

STATION II--B OTTOM INSERT In station II an operator applies thepreformed bottom 24 manually to the form 86 so that it lies within theoverhanging edge 28 of the side wall blank B as in FIG. 5, and thebottom 24 is supported in position by the overhanging edge 28 of theblank B. Insertion of the preformed bottom 24 does not in any wayinterfere with the operation of the side sealing operation shown in:FIGS. 19 to 21.

STATIONS III AND IVHEAT BOTTOM EDGE OF SIDE AND BOTTOM Precisely thesame operation takes place in stations III and IV on each of thepartially formed containers carried on the forms. In each station agenerally vertically extending arm 220 is pivotally supported at itsbottom on a pin 222, and the pin in turn is carried on the end of an arm224 which extends generally horizontally under the machine to thecentral actuator 186. The arrangement is shown in detail in FIG. 24 andis suggested diagrammatically in FIG. 4. The horizontal arm 224 ispivoted on the frame on shaft 228 in a manner similar to the horizontalarm 180 shown in FIG. 22, and the arm 224 carries a fixed link 226.Thus, when the actuator 186 moves up and down, arm 224 pivots on shaft228, and link 226 moves with it. A spring 230 connects the top of thelink 226 with the vertical arm 220, and the spring and link connectionbetween the arms 220 and 224 impart some flexibility into the actuation,which will be better appreciated below.

A heater 232 is carried on the top of the arm 220 and moves to theposition shown in FIG. 6 to apply heat directly to the adjacent edges ofthe bottom margins 38 and 40 of the bottom 24 and side wall blank Brespectively. The heater 232 directly engages those margins so as toapply heat to each. The heater 232 is moved to the operative positionfrom that shown in FIGS. 4 and 24 by, downward movement of the actuator186. When the actuator moves down, the horizontal arm 224 pivot aboutits axis 228 and carries the link 226 with it. The spring 230 in turnpulls the vertical arm 220 until the heater 232 engages the margins ofthe container. The heater 232 raises the temperature of the plasticmaterial sufiiciently to make the juncture of the bottom blank and sidewall blank molten. A coating of Teflon or other similar material on thesurface of the heater which engages the margins will prevent the plasticmaterial of the blanks from sticking to the heaters. The heating step iscarried out at each of stations III and IV so as adequately to heat theplastic for subsequent bonding. Although sufficient heat could beapplied at one station by slowing the step by step rotation of theturret, such a change would obviously adversely effect the machineoutput, and the two stage heating is used to avoid this result.

STATION VSEALING BOTTOM TO SIDE WALL In. station V the molten margins ofthe bottom blank and side wall blank are spun together by a rotatingiron 240 provided with a groove 242 on its face, which receives theadjacent margins of the blanks to form them to the contours shown inFIGS. 1 and 1B and seal them together. The rotating iron 240 is carriedon a stub shaft 244 on the upper end of arm 246 which resembles arm 220that carries the heater 232. The arm 246 is moved by horizontal lever248 through link 250 and spring 252 in a manner identical to thatdescribed above. The stub shaft 244 carries a sprocket 254 having achain 256 driven by a motor (not shown) mounted on the frame. Thus afterthe bottom margin of the assembled container is heated in stations IIIand IV, the rotating iron 240 in station V engages the margin of thecontainer, and its groove 242 spins the margin to form a liquid tightseal. In the form of iron 240 shown in FIG. 25, fins are mounted on itsperiphery to dissipate the generated heat.

STATION VI In station VI the wholly formed container is removed from theturret 84 by an operator positioned adjacent that station, and theoperator places each formed container on the secondary turret 208 whichperforms the rimming operation. It will be appreciated that when thecontainer is removed at station VI, the upper end of the side wall isnot rolled over as shown in FIG. 1, but rather the side wall is straightand terminates in a straight rim at edge 26. The rolled rimconfiguration adds significantly to the utility and acceptability of theproduct.

RIMMING TURRET The rimming turret 208 shown in FIGS. 3 and 4 includes acentral shaft 260 which carries a rotating turret plate 262 from whichdepend five basket-like container holders 264. These baskets are shownin detail in FIGS. 26 and 28. Each includes a rim 266 embedded in theturret plate 262 and has a raised lip 268 about which the upper edge ofthe container side wall is turned to form a rolled rim. A number of rodsupports 270 extend downwardly from the rim 266 and together carry base272 which supports the bottom of the formed container. The base 272 isprovided with an opening 274 to facilitate ejection of the formedcontainers after the rim is rolled.

A platform 276 is disposed above the turret plate 262 and carries thevarious sub-assemblies which combine to form the rim on the container.The several steps in the operation are conducted in five stationsidentified by the letters A through E. Briefly the functions performedin each station are as follows:

Station A-container from turret 84 loaded into holder Stations B andCupper margin of side wall heated.

Station D-heated upper margin rolled over lip 268.

Station Eful1y formed container removed.

These several steps are described in detail below in connection with theassociated parts of the machine.

The upper platform 276 does not extend over station A (as well asstation E) so as to provide access to the turret 9 platform 262 and thedepending basket holder 264 below to facilitate insertion of thecontainer to be rimmed into the holder in station A. No other functionis performed in this station.

STATIONS B AND C In stations B and C an assembly as shown in FIG. 26 isprovided. The assemblies are identical, and each is provided to directheat to the rim before the rolling operation. The assembly includes abridge 278 which supports a cylinder 280 whose piston rod 282 extendsdown through the bridge and carries heater 284. The lower surface 286 ofthe heater 284 is provided with an angular notch 288 which receives theupper edge 26 of the side wall and spans the lip 268 in the basket rim.By actuation of the cylinder 280, the piston rod 282 moves the heater284 into engagement with the upper edge 26 of the sidewall. Thus, instations B and C heat is directed to the rim prior to the rollingoperation which is carried out in station D.

STATION D--RIM ROLLING The apparatus mounted on the platform 276 instation D is shown in detail in FIG. 27. This assembly resembles theassemblies of FIG. 26 in that a bridge 290 is provided which supportscylinder 292 whose piston rod 294 extends down through the bridge andcarries a rotatable plate 296. A sleeve 298 surrounds the piston rod 294within the bridge 290, and the sleeve 298 includes a verticallyextending slot 300 which receives a pin 302 carried by the piston rod. Asprocket 304 is secured to the lower end of the sleeve 298 immediatelyabove the platform 276, and a chain 306 driven by motor 308 impartsrotation to the sleeve 298. By means of the pin and slot connectionbetween the sleeve and piston rod, rotation of the sleeve impartsrotation to the rod and consequently to the rim rolling plate 296.

The lower surface of the plate 296 includes a rim rolling groove 310which engages the previously heated upper edge of the side wall of thecontainer, and rotation of the plate 296 causes the edge 26 to roll overthe lip 268 of the basket, which supports the container. To dissipatethe heat generated by this operation,. fins 312 are preferably providedon the upper surface of plate 296.

STATION E In station E the formed container with the rolled rim isremoved. In FIG. 28 the assembly for ejecting the container isillustrated. A cylinder 316 is mounted on the lower platform 314 belowthe turret plate 262, and the piston rod carries a lift 218 of smallenough diameter to be able to enter the basket 264 through the opening274 provided in its base 272. The lift is designed to engage the bottomof the container disposed in the basket in station E and lift thecontainer partially out of the basket so that it may be readily graspedby an operator and be removed from the machine. The same operator whoremoves the containers from station VI of the main turret 84 anddeposits them in station A of the secondary turret may also remove thefully formed containers from station E.

FABRICATION OF CONTAINER 50 The foregoing description of the machine hasbeen presented as it may be utilized in the manufacture of the containerof FIG. 1. To fabricate the container of FIG. 2, the sequence of stepsperformed on turret 84 is somewhat changed. While in the proceduredescribed the preformed bottom is inserted Within the overhanging edgeof the side wall blank B in station II, to fabricate the container ofFIG. 2 the preformed bottom 54 is mounted on the form before the sidewall. Therefore, in station VI in accordance with this alternate method,the preformed bottom is placed on the end of the form, which is shapedto receive it, as shown in FIG. 29. Thus, the end 330 of form 332 isspecially contoured to receive the bottom 56.

10 In station I the side wall is applied as in the previously describedoperation so that the container parts appear as in FIG. 30.

Next in stations II-IV, just as described above, the side wall lappedseam is formed, and in station III the bottom margin of the side wallmay be heated by heater 334 as suggested in FIG. 31. In station IV theforming plate 336 may perform its function as suggested in FIG. 32 toroll the margin of the side wall blank over and seal it to the bottom.In station V the formed container may be removed and placed in station Aof the secondary turret 208. The several rim rolling steps are asdescribed above.

In the foregoing description the method and apparatus of this inventionhave been described in sufficient detail to enable a person of ordinaryskill to practice this invention. It is to be appreciated that changesmay be made in the method and apparatus within the scope of thisinvention, and the invention is not limited to the manufacture of thecontainers of FIGS. 1 and 2. Thus, the machine and method described maybe used to manufacture containers of a very wide variety of shapes andsizes other than the conical shape shown, i.e., square, rectangular,oval, etc. The different shapes obviously would involve the use of formsof other shapes. It would not be practical to use spinning tooling withother shapes, but sealing and rimming may be carried on withoutspinning, although spinning makes these operations less critical and thetooling less costly.

What is claimed is:

1. A container forming machine comprising a frame,

a turret mounted for rotation on the frame,

a plurality of forms having side wall and bottom wall surfaces mountedon the turret and each adapted to receive a side wall blank about itsside wall sulface,

a first station on the frame adjacent the turret and means in thatstation for applying a blank to each form as each form enters saidstation,

a magazine mounted on the frame in the first station for holding a sidewall blank above the form in that station,

means for removing a blank from said magazine,

said means in the first station including said removing means andforming means for partially forming each blank into a cone andthereafter placing the partially formed conical side wall blank on theform in that station,

sto means mounted on each form for registering the blanks on them in thedesired position,

heating and clamping means mounted on the frame in association with eachform for heating the sides of the blank by positioning a radiant heaterbetween facing surfaces of the blank to heat said facing surfaces to belapped and thereafter clamping said facing surfaces together in lappedrelation to form a lapped side seam for the container blank,

a second station on the frame disposed adjacent the first station inwhich station a bottom blank may be applied to the forms as they entersaid station with the bottom including a peripheral flange lying in faceto face contact with the inner surface ofthe side wall blank on the formover at least a portion of the axial extent of the flange when both sidewall and bottom blanks are in place on the forms,

a heater mounted on the frame in a third station adjacent the turret andmovable to engage at least the side wall blank on the turret to make itmolten at the region where it engages the bottom as each form is in thatstation,

a forming tool mounted in a fourth station on the frame adjacent theturret for shaping and sealing the molten portion of at least the sidewall while on the form and immediately after it is heated to preciselyshape the union between the bottom and side wall,

and a fifth station adjacent the frame through which each form passesfor removing the container on each form.

2. A container forming machine as described in claim 1 furthercharacterized by said second station following said first station insequence about the turret so that the bottom is applied to the formafter the side wall blank.

3. A container forming machine as described in claim 1 furthercharacterized by said second station preceding the first in sequenceabout the turret so that the bottom is applied to the form before theside wall blank.

4. A container forming machine as described in claim 1 furthercharacterized by a second turret mounted on the frame,

and means mounted on the frame about the second turret for rolling therims of containers transferred to it.

5. A container forming machine as described in claim 1 furthercharacterized by said heating and clamping means including a pair ofclamping bars with each form and movable therewith,

and a heater mounted on the frame,

and means connected to the bars and heater for causing them to operatesequentially to first hold one edge of a side wall blank on the form,then heat the adjacent edges of the blank, and next firmly press theedges together to seal them in overlapping relationship.

6. A container forming machine as described in claim 4 furthercharacterized by said second turret including a plurality of basketshaped holders for receiving the containers formed on the first turret,

a heater on the frame adjacent the second turret and means for moving itinto engagement with the upper edge of the side wall of the container,

and forming means on the frame adjacent the second turret for rollingthe heated edge into a down turned rim.

7. A container forming machine as described in claim 6 furthercharacterized by said forming means comprising a rotatable plate havinga groove for receiving the upper edge,

and means for rotating the plate as it engages the edge to turn it over.

8. A container forming machine as described in claim 1 furthercharacterized by said means in the first station including a suctiondevice for carrying the blank from the magazine,

a pair of folding plates disposed below the magazine which move towardand away from one another to receive the blanks and form them into asubstantially conical form,

and drive means connected to the suction device and folding plates formoving the device from the magazine to the plates and for moving theplates together to form the blank.

9. A container forming machine as described in claim 8 furthercharacterized by said drive means moving said plates while carrying ablank in the direction of the form to deposit the blank on the form.

References Cited UNITED STATES PATENTS 2,665,738 1/1954 Caskin 56-4993,533,332 10/1970 Young et al. 93-393 3,468,226 9/1969 England et al93-393 3,343,465 9/1967 Albert 93-393 3,336,847 8/1967 Durat 93-3932,942,530 6/1960 Bodendoerfer 93-393 3,505,933 4/1970 Schmidt 93-3933,049,979 8/ 1962 Sayford, Jr 93-393 3,438,824 4/1969 Balamuth 156-693,289,552 12/1966 Corazzo 93-393 2,608,914 9/1952 Merkle 93-365 R3,063,347 11/1962 Cummings 93-393 3,065,677 11/1962 Loeser 93-365 R3,658,615 4/1972 Amberg 156-218 CHARLES E. VAN HORN, Primary Examiner B.I. LEWRIS, Assistant Examiner US. Cl. X.'R. 156-499, 571

1. A container forming machine comprising a frame, a turret mounted forrotation on the frame, a plurality of forms having side wall and bottomwall surfaces mounted on the turret and each adapted to receive a sidewall blank about its side wall surface, a first station on the frameadjacent the turret and means in that station for applying a blank toeach form as each form enters said station, a magazine mounted on theframe in the first station for holding a side wall blank above the formin that station, means for removing a blank from said magazine, saidmeans in the first station including said removing means and formingmeans for partially forming each blank into a cone and thereafterplacing the partially formed conical side wall blank on the form in thatstations, stop means mounted on each form for registering the blanks onthem in the desired position, heating and clamping means mounted on theframe in association with each form for heating the sides of the blankby positioning a radiant heater between facing surfaces of the blank toheat said facing surfaces to be lapped and thereafter clamping saidfacing surfaces together in lapped relation to form a lapped side seamfor the container blank, a second station on the frame disposed adjacentthe first station in which station a bottom blank may be applied to theforms as they enter said station with the bottom including a peripheralflange lying in face to face contact with the inner surface of the sidewall blank on the form over at least a portion of the axial extent ofthe flange when both side wall and bottom blanks are in place on theforms, a heater mounted on the frame in a third station adjacent theturret and movable to engage at least the side wall blank on the turretto make it molten at the region where it engages the bottom as each formis in that station, a forming tool mounted in a fourth station on theframe adjacent the turret for shaping and sealing the molten portion ofat least the side wall while on the form and immediately after it isheated to precisely shape the union between the bottom and side wall,and a fifth station adjacent the frame through which each form passesfor removing the container of each form.